Flap door for locomotive furnaces and the like



G. DE GRAHL' FLAP DOOR FOR LOCOMOTIVE FURNACES AND THE LIKE Jpne 8 1926.

Filed March 11. 1925 2 Sheets-Sheet 1 2 Sheets-Sheet 2 G. DE GRAHL FLAP DOOR FOR LOCOMOTIVE FURNACES AND THE} LIKE Filed March 11. 1925 June 8 1926.

Patented June 8, 1926.

UNITED STATES GUSTAV DE GRAHL, OF BERLIN-ZEHLENDORF-WEST, GERMANY.

FLAP DOOR FOR LOCOMOTIVE FURNACES AND THE LIKE.

Application filed March 11, 1925, Serial N0. 14,817, and in Germany May 24, 1924.,

It is of the greatest importance to keep the flap fire doors of locomotive cool, as there is a danger, if they become heated, of deformations being caused. For, even if there is only a slight deformation, the door will no longer close tightly and the locking means provided on the swinging device for the door will no longer work.

For the above reason such a door is made saddle-shaped and is placed as far as possible outside the actual furnace space. Large air shafts have also been provided on either side of the fire hole in the door frame for causing air to play laterally on the flap door and to sweep along it.

A further advance in the art was constituted by the construction, in which the flap door was provided with double walls and air was introduced between the double walls through lateral slits in the door frame, which then escaped through openings in the inner wall of the door into the fire space. The quantity of air entering the door was regulated by fiaps operated by hand.

Furthermore, it has been suggested heretofore to provide air-chests in the frame of a door for locomotive furnaces and to allow the air to flow from the said chests into and through the double-walled or hollow door, and, besides that, to provide means for cooling the outer surfaces of the protective ring for the fire hole rivets by means of the air from the airshafts of the door frame.

None of these arrangements however are sufiicient to meet the demands made on such a door at the present time. \Vhen the cooling air is only guided laterally on to the door, most of it does not reach the door at all in spite of the provision of guiding surfaces and the like, as, when the engine is working hard, it is carried away by the intermittent draught of the blast pipe straight to the fire tubes. A similar effect takes place at the air outlet openings in the inner wall of the door, where the air also does not reach the middle and more particularly not the lower end of the door, but is sucked away to the fire space beforehand. It has also been found that the one-sided cooling of the outer surface of the protective ring for the door hole rivets is not sufficient, the said ring being soon destroyed by the great heat at this place.

The greatest disadvantage of the arrangement used hitherto consists in the regulation of the air supply, as the flaps for the. ad-

mission of the cooling air must be opened either by hand or by the partial vacuum in the fire-box of the locomotive. Both arrangements are most inadequate. If the attendant should forget to open the flaps, there rs no cooling of the fire-door at all. WVhen the opening of the flaps is effected by the partial vacuum in the fire-box, the flaps are closed just when the development of heat in the fire-box is greatest. This is the case, when the locomotive is travelling with a closed governor without steam, for instance on a down grade, where no partial vacuum or only a slight partial vacuum is produced in the fire-box. If the locomotive has previously been travelling up a grade, which he cessitated firing up considerably, and the locomotive passes from an upward to a downward grade, there will be a dangerous accumulation of heat from the strongly drawn up fire, which will react on the flap door, which is not cooled or only slightlv so, and will cause its destruction.

According to the invention. these drawbacks are overcome by rendering the cooling of the important parts of the door independent of the personal element and of the state of the draught in the firebox, by causing the surface of the flap door to be intensively swept over by air and by cooling the protective ring for the fire hole rivets, which is most exposed to destructive action. Special provision is also made for securely locking the flap door in its most important positions and for protecting the door as much as possible during its frequent movements.

The accompanying drawings illustrate the invention by way of example,

Figure 1 being a vertical crosssection through the door frame and the flap door, taken on the line II in Fig. 2 which is a partial view of the door frame, partly in section;

Fig. 3 is a fragmentary sectional view similar to Figure 1, but on an enlarged scale, on the line I-I also,

Fig. t is a section taken on the line IVIV in Figure 2, on an enlarged scale, and with the door in closed position whilst,

Fig. 5 is a view similar to Figure 4 but with the door in open position.

In a known type of door frame 1 a saddleshaped flap door consisting of tWo walls 2 and 3 is mounted so as to rotate on a. hollow shaft 4. y In the upper part of the frame an elongated inlet 5 is provided, which is adapt ed to be closed by means of a flap 6. In the hollow shaft 1 slits 7 and 8 are provided. hen the flap door is in the closed position, the former coincides with the inlet and the latter is approximately opposite the former and opens into the hollow space 9 lying between the two walls 2 and 3. On the shaft 10 of the flap 6 a strong spring 11 is provided, which seeks to raise the flap 6 and to hold it for instance in the position shown in Fig. 1. In the closed position the flap 6 is held by a detent 12, which has an arm 13. The latter is kept by the action of a spring let continuously in contact with a. cam 15 on a shaft 16. The shaft 16 is coupled with the opening device for the door in such a manner that each time the flap door is opened the said shaft is turned in the direction of the arrow 17 so that by the action of the cam 15 the detent 12 is disengaged, whereby the flap 6 is liberated and is thrown up by the spring 11.

The means for moving the door are the following: As is well known, it is important that such a flap door he held securely locked in the closed position, so as not to be forced open by the draught of the blast pipe. For this purpose a disk 18 with a projecting part 19 is rigidly fixed on the hollow shaft 4. On the cam shaft 16 a detent 20 is fixed, which, when the door is in the closed position, engages behind the said projecting part and thereby locks the door in the closed position.

For opening the door the locking means thereof must be first released and for this purpose the door weight 21 with the handle 22 is provided with a guide 23 having several notches 24. The weight 21 is also provided with a driving member 25, which is adapted to move between two projections 26 and 27 on the disk 18 and carries the latter along with it on the weight 21 being rocked, after the weight 21 has already moved through an angle on. Shortly before the weight is moved through this angle a roller 28, which is provided on the detent 20 and runs on a guide 23, disengages the detent, thereby releasing the disk 18 and with it the shaft 4 of the flap door, so that they can rotate and so that the door is thrown up by the action of the weight 21. On the shaft 16 a torsion spring not shown is provided, which seeks to press the detent 2O always in the direction of the arrow 29 against the guide provided on the weight 21 for the roller 23. In this way by means of the detent 20 and the roller 28 and through the latter engaging in the notches 24 the door is held in its open position or in an intermediate position, so as to be secure even against shocks.

In order to take up and reduce the violence of the severe blow, when the flap is opened and closed, a buffer device is pro On the disk 18 a dog is provided and a similar dog 36 on Y the weight 21, the former of which, on the door being closed, rests on the top of the sleeve 31, displacing the latter and pressing the double spring. On the door opening, the double spring first expands and is then again compressed by the dog 36 striking against the lower edge of the sleeve 32, whereby the blow of the door is taken up.

The arrangement acts in the following manner On the door being opened, the bolt 16 is turned by the detent 20 in the direction of the arrow 17, the flap 6 is released and flies up under the action of the spring 11. lVhen the door is closed again, after the stoking operation, the flap 6 remains in the open position and cooling air enters in the direction of the arrow 37 into the hollow space 9, sweeps over the inner wall 3 of the door, while passing through the whole of the ho]- low space, thus thoroughly cooling it, and leaves through a narrow slit 38 at the lower edge of the door in the direction of the inner surface of the protective ring 39. By this means the latter is effectively cooled at the surface, which is most exposed to the heat. A portion of the air entering through the inlet 5 passes in the direction of the arrow 40 into a circulating passage 41 on the door frame and passes from there in the direction of the arrows 42 to the outside of the protective ring 39, thus cooling this surface as well.

Even if the attendant should close the flap 6 by hand it cannot remain closed long, since each time the fire is stoked the said flap flies open again automatically. On the other hand, while the engine is being heated up, in which case owing to the lack of any draught fumes and smoke could escape to the foot-plate, the attendant can always close the flap again by a simple movement after the door has been opened.

I claim 1. A flap door, more particularly for 10- comotive furnaces and the like comprising in combination a door frame, a protective ring for the fire hole rivets, a saddle-shaped double-walled flap door having inlets through which air enters the hollow space between the walls of the door and a narrow slit at the lower edge of said door for emitting the air, when the door is shut, upon Laeaeaa said protective ring for the fire hole rivets, a flap for normally closing the air inlets of the said double-walled door, and means for positively opening the said flap when the door is being opened.

2'. A flap door, more particularly for locomotive furnaces and the like comprising in combination a door frame, a protective ring for the fire hole rivets, a saddle-shaped double-walled flap door having inlets through which air enters the hollow space between the walls of the door, a narrow slit at the lower edge of said door for emitting the air, when the door is shut, upon said protective ring for the fire hole rivets, a hollow shaft for mounting said door shaft having slots for the admission of air into said hollow shaft and into the space between the walls of said door, a spring controlled flap for normally closing the air slits in the hollow shaft, means for opening said flap when the door is being opened.

3. A fla 3 door, more particularly for 10- comotive furnaces and the like comprising in combination a door frame, a protective ring for the fire hole rivets, a saddle-shaped double-walled flap door having inlets through which air enters the hollow space between the walls of the door, a narrow slit at the lower edge of said door for emitting the air, when the door is shut, upon said protective ring for the fire hole rivets, a hollow shaft for mounting said door said shaft having slots for the admission of air into said hollow shaft and into the space between the walls of said door, a disk rigid- 1y fixed on said hollow shaft, a locking projecting part of said disk, two other projcctions on said disk, a door weight rotatably mounted on said hollow shaft, a driving member on said weight adapted to move between said two projections on said disk, a detent pivotally mounted on the door frame engaging with said locking projecting part of the disk for securely holding the door in the closed position, a spring-controlled flap for normally closing the air slits in the hollow shaft, and means for releasing said flap when the door is being opened.

4. A flap door, more particularly for locomotive furnaces and the like con'iprising in combination a door frame, a protective ring for the tire hole rivets, a saddle-shaped double-walled flap door having inlets through which air enters the hollow space between the walls of. the door, a narrow slit at the lower edge of said door for emitting the air. when the door is shut, upon said protective ring for the fire hole rivets, a hollow shaft for mounting said door said shaft having slits for the admission of air into said hollow shaft and into the space between the walls of said door, a disk rigidly fixed on said hollow shaft, a locking projecting part of said disk, two other projections on said disk, a door weight rotatably mounted on said hollow shaft and having a guide having several notches, a driving member on said weight adapted to move between said two projections on said disk, a detent pivotally mounted on a shaft on the door frame engaging with said locking projecting part of the disk for securely holding the door in the closed position, a roller on said detent running on said guide of the door weight and disengaging said detent, a spring-controlled flap for normally closing the air slits in the hollow shaft, a cam on the shaft of said detent acting upon a spring-controlled detent for releasing the said flap when the locking detent is disengaged from said locking projection.

A flap door, more particularly for 10- comotive furnaces and the like comprising in combination a door frame, a protective ring for the fire hole rivets, a saddle-shaped double-walled flap door having inlets through which air enters the hollow spacebetween the walls of the door, a narrow slit at the lower edge of said door for emitting the air, when the door is shut, upon said protective ring for the fire hole rivets, a hollow shaft for mounting said door said shaft having slits for the admission of air into said hollow shaft and into the space between the walls of said door, a disk rigidly fixed on said hollow shaft, a locking projecting part of said disk, two other projections on said disk, a door weight rotatably mounted on said hollow shaft and having a guide having several notches, a driving member on said weight adapted to move between said two projections on said disk, a detent pivota-lly mounted on a shaft on the door frame engaging with said locking projecting part of the disk for securely holding the door in the closed position, a roller on said detent running on said guide of the door weight and disengaging said detent, a spring-controlled flap for normally closing the air slits in the hollow shaft, a cam on the shaft of said detent acting upon a spring-controlled detent for releasing the said flap when the locking detent is disengaged from said locking projection, an abutment on said disk on said hollow shaft of said door, and an abutment on said door weight said two abutments acting upon the opposite ends of a spring-controlled buffer bolt.

In testimony whereof I aflix my signature.

GUSTAV on GRAHL, 

